Water Leak Testing
US-BES uses a systematic approach to discovering water leaking through exterior walls and roofs. Our process is practical and efficient. It’s good to note that this form of testing is also known as a forensic or technical assessment, inspection, investigation, or examination in the building science industry. There are several ways to describe the process of exterior water testing, which can be confusing for the layperson.
It is critical for the professional performing these tests to clearly understand how a building’s components are assembled. How many layers (i.e., wythes) of masonry are on the wall? Is it a cavity wall or a solid loadbearing masonry wall? Is it built with a backup of concrete block units, drainage space, and brick veneer? Are there vapor barriers? Is there flashing on the lintels? Do the lintels have end-dam flashings? What is the condition of sealants at control joints and the perimeter of window/door frames? Have they deteriorated, or are they functioning as intended? These are some of the general contingencies a forensic professional should be familiar with in the construction assembly of buildings before performing water testing on exterior walls.
Water Infiltration
Most of the water infiltration we discover in masonry is located at the flashing points and/or damaged masonry. Deterioration of flashing at window lintels, door heads, expansion joints, parapet walls (coping tops and lower through-wall flashing), and cracks in the masonry. Flashing at the joists between floors in multi-story buildings can leak if they are not properly installed. Thus, generating problems inside the building’s assembly.
Cavity walls have been discovered with the drainage space partially or fully mortared. These issues produce an avenue for rainstorm water to enter through the mortar joints and travel into the interior spaces. This problem is known as bridging. It is when water flows between two surfaces that should be separated and/or contain a break. We all know that water flows in the direction of least resistance. If the elements that make up the walls are poorly constructed, rainstorm water will flow onto surfaces that can easily travel with the least obstructions.
While masonry exterior walls act as the first defense against rainstorm water penetrating the interior surfaces, they are variable to swing in temperatures. Expansion and contraction due to freezing and thawing create excessive strains in the mortar joints and masonry units (such as bricks or blocks). If the mortar joints around the masonry units are stiff and hard, the masonry units will likely crack or spall from the internal stresses. Ideally, mortar in the joints should be soft enough to absorb the stresses. Unfortunately, in many of the cases, we have investigated, the mortar is as strong or stronger than the masonry units or stronger. That means that the masonry units suffer the deterioration rather than the mortar in the joints.
Many think that the exterior masonry of a building is an indestructible waterproofing system. Nothing could be further from the truth. This is contradictory to the understanding of the building material and its behavior. Masonry units and mortar absorb water from storms, wind, snow, and light airborne moisture. Exterior walls are designed to allow water to infiltrate and be directed down into drainage spaces. The flow of water runs down through the wall flashing and exits by the weep systems.
Interview
Before we begin the water testing, we interview the Homeowners and/or property management personnel. These are a sample of the questions we ask:
Could you give us a walkthrough of the interior spaces where you have observed rainstorm water entering?
When do you recall the last time that you witnessed water leaking into your space?
Was the water entering from the ceiling, walls, windows, or doors?
When it rains, do you always see the water leaking?
If water is entering through the ceiling, where do you observe a water pond on the floor? Near the walls or at the center of your space?
Have the exterior walls been coated with a water-repellent sealer? If yes, how old is it, what’s the product name and who installed the sealer? Do you have documentation of the application? That is, contractor’s contract and manufacturer’s warranty.
Once we have some idea of the locations or location of the water leakage sources, the next step is to check the exterior wall around the building. We attempt to visually identify the outside walls opposite to where the homeowner observed rainstorm water entering the building. If water is assumed to be entering through the exterior masonry walls, we inspect the following:
Cracks and spalls in masonry units (i.e., brick, limestone, terra cotta, concrete blocks, etc.)
Hairline cracks in the masonry mortar joints
Expansion joint’s sealant condition (i.e., loss of adhesion, brittle, cracked, etc.)
Perimeter sealant condition along the window and door frames (i.e., loss of adhesion, brittle, cracked, etc.).
If water is assumed to be entering through the roofing, we inspect the following:
Does the roof have planters, how many, and what size are the planters?
Does the roof have a patio deck? How big?
Does the patio deck have insulation supports between wood framing and roofing membrane?
Is there outdoor furniture on the patio deck? How many pieces and sizes?
These are a few questions that we may ask the homeowner.
By asking these questions, we create a picture to help us understand the external stresses that impact the roofing membrane. This helps us narrow down and isolate the points where water enters the roofing.
Water Testing Setup
Once we have a good solid understanding of the construction and the approximate locations of the water leaks, we begin to set up and stage for the physical water testing before turning on the water for the testing spray bar.
We cover the interior space and furniture with heavy-duty plastic sheets. Furthermore, when water appears through the drywall, we immediately collect it into buckets and stop the test. We have towels and rags at our disposal in the unlikely event that a small portion of water droplets escape the plastic sheets. The goal is to protect the homeowners’ personal property from small droplets of water.
Actual Water Test
These tests are run with two staff members, one in the interior space and another at the exterior of the building.
One staff member stays inside the space to monitor the initial water entering and quickly collect any water that does. When physical water is observed entering, they call out to stop the water testing. Another staff member is outside the building and waits for the command to turn off the water from the spray bar.
Exploration
The next phase is in the exploration and discovery portion of the test. Once we have observed water entering through the drywall or ceiling, we surgically cut a small opening large enough to observe and investigate how the water was entering. If it is near a window, the surgical opening is performed near the steel lintels to view the waterproofing flashing from the opposite side. We inspect for punctures and rips in the rubberized flashing membrane. If the water enters through the drywall ceiling, we carefully cut an opening to view and inspect how water entered through the underside of the roof deck.
Testing Procedures
US-BES follows the testing requirements stated in the American Society for Testing & Materials (ASTM) and American Architectural Manufacturers Association (AAMA).
The water tests are performed as follows:
By following the *AAMA-501.2-03-Field Check Water-Hose Test and the *ASTM E2128 – 01a - Standard Guide for Evaluating Water Leakage of Building Walls. *RILEM used to evaluate water absorption rates on existing masonry building materials.
*American Architectural Manufacturers Association
*American Society for Testing and Materials
*(Reunion Internationale des Laboratoires d’Essals et de Recherches sur les Materiaux et des Constructions - International Union of Testing and Research Laboratories for Materials and Structures).
Testing Equipment
The equipment used for the water testing of exterior walls is as follows:
A grid-shaped spray rack of ¾” galvanized pipes, from 6’-6” to 11’-6” foot long, containing 14-brass nozzle spray tips at 16” O.C. The nozzles are WL ¼”, 90 degrees cone shape by the manufacturer Bete. The handheld wand is manufactured by Monarch with a Type B-25, #6.030 brass nozzle spray tip.
Completion of Test
After testing and with the gathered evidence, US-BES cleans up the interior space and takes our equipment away. Within a couple of weeks, the homeowner receives a Forensic Water Infiltration Investigation Report. The report describes the investigation process, findings, repair recommendations, and a restoration budget. At the homeowner’s request and approval, the report is submitted to US-BES’s sister company (US-CES) to develop a formal construction restoration proposal. Once the proposal is signed and approved by the homeowner, US-CES implements the actual construction restoration repairs.
Water infiltration issues developed in the cement blocks that severely deteriorated the masonry walls. We performed several ASTM E 2128 (American Society for Testing and Materials) water infiltration investigation tests and discovered specifically the locations of critical areas. Submitted a report with findings and methods of repairs.
Several decades of winter’s freezing and thawing cycles have eroded the stone’s mortar joints and flashing. Water leaks had developed in many locations. We performed ASTM E 2128 leak inspections. Submitted a report with findings and methods of repairs.
Discovered that in windy rainstorms, water penetrated the exterior masonry mortar joints, traveled throughout the cement block backup wall, and exited into the interior drywall surfaces. We provided corrective detailed drawings and aided in the repairs process to prevent further water infiltration.
Performed several water infiltration tests using a handheld nozzle on the brick masonry facade complying with the American Architectural Manufacturers Association tests (AAMA - 501.2-03-Field Check Water Hose Test). After discovering very fine hairline cracks in the mortar joints that were allowing water to penetrate the masonry and infiltrate the interior of the building, we developed a low cost and effective scope of work to repair the mortar joints and manage the restoration work.